The England and Wales Cricket Board (ECB) confirmed that the pair had informed them of the decision in the last few days.

The ECB said in August that the tour would continue as planned following a "security review".

As a result of the withdrawals, Jos Buttler will captain the one-day side, with the squads for the one-day and Test series to be named on Friday.

All other centrally contracted players have agreed to travel with Stuart Broad, Moeen Ali, Chris Jordan and Liam Dawson all publicly confirming they will tour Bangladesh.

Safety concerns emerged last month when 29 people were killed in a terrorist attack in Bangladesh's capital Dhaka, one of the two cities which will play host to matches during England’s tour, when five militants opened fire and took hostages at a café.

Twenty of those who lost their lives were hostages and the incident was described as the worst attack in Bangladesh’s history.

Australia cancelled a tour to the country back in October of last year in the wake of terrorist attacks in Dhaka, which the so-called Islamic State claimed responsibility for.

England's tour will feature three one-day internationals followed by two Test matches.

"While we understand and respect Eoin and Alex's decision, we are disappointed that they have made themselves unavailable for selection for the Bangladesh tour," said England director of cricket and former skipper Andrew Strauss.

“We have had open and honest conversations with all the players about security arrangements and at this stage we are not expecting any other individuals to withdraw.

“The safety and security of players and staff is of the utmost importance to ECB. 

"We will continue to monitor the situation in Bangladesh, take advice and consider the appropriate steps up to and throughout the five weeks on tour.”

Morgan has experienced security concerns before. 

He was close to a detonation of a bomb during a match in Bangalore when playing in the Indian Premier League in 2010 as well as violence while playing in the country around the time of national elections three years later.

"In 2010, we played an Indian Premier League game in Bangalore and a bomb went off in the ground," Morgan said last week.

"We left and went straight to the airport.

"Another one was playing domestic cricket in Bangladesh during political elections and things were incredibly violent."

England are due to fly out on September 29, with the one-day series starting on October 7 and the Test series on October 20.